ELCOM Euro-500T Handy User manual

Euro-500T Handy
Service manual
© Elcom Ltd.
Version 1.0
Euro-500 Handy

Neither this manual, or any part of it, may be copied or distributed without
the consent of the Elcom company.
All rights of Elcom Ltd. are reserved.

© Elcom Ltd.
Service manual
3
Euro-500T Handy
Table of contents
1 INTRODUCTION ............................................................................................................................ 5
1.1 Euro-500T Handy cash register technical parameters ............................................................ 5
1.2 System configuration ................................................................................................................. 5
1.3 Cash register block diagram...................................................................................................... 5
2 CIRCUIT SCHEMES AND FUNCTIONS ........................................................................................ 6
2.1 Connection circuits .................................................................................................................... 6
2.1.1 External power supply ..................................................................................................... ............. 6
2.1.2 Primary connection circuit ............................................................................................................ 6
2.1.3 Voltage stabilizer .......................................................................................................................... 7
2.1.4 Printer connection circuit .............................................................................................................. 8
2.1.5 Secondary connection circuit ....................................................................................................... 8
2.1.6 Circuit for connecting the fiscal memory ....................................................................................... 9
2.1.7 Power supplies characterisation ................................................................................................... 9
2.2 Micro-controller and its support circuits ................................................................................ 10
2.2.1 E-500N micro-controller ............................................................................................................. 10
2.2.2 Memory circuits .......................................................................................................................... 12
2.2.3 System start and outage ................................................................................................... ......... 13
2.2.4 Current time circuit ..................................................................................................................... 13
2.3 Input-Output circuits ................................................................................................................. 14
2.3.1 Print control circuits .................................................................................................................... 14
2.3.2 Keyboard .................................................................................................................................... 16
2.3.3 Displays ..................................................................................................................................... 17
2.3.4 Communication circuits .............................................................................................................. 20
2.3.5 Interconnection of FM circuits ..................................................................................................... 21
2.3.6 Other circuits ............................................................................................................................. 22
3 THE MLT-288 THERMAL PRINTER ............................................................................................ 24
3.1 Basic layout ............................................................................................................................... 24
3.2 Thermal head ............................................................................................................................ 24
3.2.1 Thermal head composition ......................................................................................................... 24
3.2.2 Thermal head data processing ................................................................................................... 25
3.2.3 Print data and their position ........................................................................................................ 25
3.2.4 Thermistor layout ....................................................................................................................... 25
3.2.5 Time chart .................................................................................................................................. 25
3.3 Paper shifting ............................................................................................................................ 26
3.3.1 Stepping motor layout ................................................................................................................. 26
3.3.2 Excitation sequence ................................................................................................................... 26
3.3.3 Control circuit ............................................................................................................................. 26
3.4 Sensor of head position ........................................................................................................... 27
3.5 Sensors of paper ribbon end ................................................................................................... 27
3.6 Overall time chart ...................................................................................................................... 27
3.7 Printer connectors .................................................................................................................... 28
3.7.1 Thermal head connector ............................................................................................................ 28
3.7.2 Motor and sensors terminal ........................................................................................................ 29
3.8 How to clean thermal head ...................................................................................................... 29
4 MODULE (RE)INSTALLATION .................................................................................................... 30
4.1 Dismantling the cash register .................................................................................................. 30
4.2 Accumulator replacement ........................................................................................................ 32
4.3 Printer replacement .................................................................................................................. 33
4.4 Motor replacement .................................................................................................................... 34
4.5 Electronics mainboard replacement ....................................................................................... 35
4.6 EPROM replacement ................................................................................................................ 36
4.7 Replacement of damaged SRAM or replacement of SRAM with higher capacity .............. 36

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© Elcom Ltd.
Service manual
Euro-500T Handy
4.8 NiCd battery replacement ........................................................................................................ 37
4.9 Keys and keyboard replacement ............................................................................................ 37
4.10 Replacement of displays .......................................................................................................... 39
4.10.1 Replacement of Euro-500T Handy (segment/segment) displays ................................................ 39
4.10.2 Replacement of Euro-500T Handy (alpha/segment) displays ..................................................... 40
4.11 Cash register connectors ........................................................................................................ 41
4.11.1 Connectors on mainboard of electronics ....................................................................................41
4.11.2 Connectors for connecting external appliances .......................................................................... 41
4.12 Back-light installation of segmented LCD display ................................................................ 42
4.13 Connecting of external drawer ................................................................................................ 43
4.14 Connecting of external keyboard ............................................................................................ 44
4.15 Interconnecting of Euro-500T Handy and PC through RS-232 interface ............................ 45
4.16 Connecting of scanner and scales through RS-232 interface ............................................. 45
5 CASH REGISTER TESTING ........................................................................................................ 46
5.1 Test of displays ......................................................................................................................... 46
5.2 Printer test ................................................................................................................................. 47
5.2.1 Testing of printing ....................................................................................................................... 47
5.2.2 Testing of scanning the thermal printer head position .................................................................. 47
5.2.3 Testing of paper ribbons sensors .......................................................................................... ...... 48
5.3 Keyboard tests .......................................................................................................................... 48
5.3.1 Keyboard test 1 .......................................................................................................................... 48
5.3.2 Keyboard test 2 .......................................................................................................................... 49
5.4 Communication interface tests ............................................................................................... 50
5.4.1 Test of RS-232C serial interface for the PC ................................................................................50
5.4.2 Test of RS-232C serial interface for the scanner and electronic scales ...................................... 50
5.4.3 The test of serial interface for the external PC keyboard ............................................................. 51
5.5 Test of cash register drawer .................................................................................................... 52
5.6 Fiscal memory tests .................................................................................................................. 52
5.6.1 Tests of data reading from the fiscal memory ............................................................................. 52
5.6.2 Test of data recording to the fiscal memory ................................................................................53
5.6.3 The operating voltage control for the fiscal memory .................................................................... 53
5.6.4 The test of the control signals I for the fiscal memory ................................................................. 54
5.6.5 The test of the control signals II for the fiscal memory................................................................. 54
5.7 Test of the control sum of EPROM memory ........................................................................... 55
5.8 Battery tests .............................................................................................................................. 55
5.8.1 The test of battery condition ........................................................................................................ 55
5.8.2 The test of VCC1 supply ............................................................................................................. 55
6 FAILURE REMOVAL .................................................................................................................... 56
6.1 Failures in supply section ........................................................................................................ 56
6.2 Failures of micro-processing system ..................................................................................... 57
6.3 Failures of print ......................................................................................................................... 58
6.4 Failures of visual display ......................................................................................................... 60
6.5 Failures of keyboard ................................................................................................................. 60
6.6 Failures of communication ...................................................................................................... 61
6.7 Failures of current date and time............................................................................................. 61
6.8 Other failures ............................................................................................................................. 61
7 THE LISTS OF PCB COMPONENTS .......................................................................................... 62
7.1 Classification of cash register components .......................................................................... 62
7.2 List of electronics mainboard components ........................................................................... 62
7.3 List of keyboard components..................................................................................................69
7.4 List of display segmented module components ................................................................... 69
7.5 List of components on board of connectors ......................................................................... 70
7.6 List of components on interconnection board ...................................................................... 70
7.6.1 List of components on interconnection board of Euro-500T Handy (segment/segment) .............. 70
7.6.2 List of components on interconnection board of Euro-500T Handy (alpha/segment) ................... 71

© Elcom Ltd.
Service manual
5
Euro-500T Handy
1 Introduction
1.1 Euro-500T Handy cash register technical parameters
The Euro-500T Handy is a portable electronic cash register with the following technical parameters:
primary connection external adapter 230 V, 50-60 Hz/12 V, 1200 mA
internal connection NiMh accumulator 7,2 V, 1500 mAh
or lead accumulator 6 V, 1200 mAh
maximum power consumption 10 W
micro-processing system 16-bit micro-controller, 256 kB EPROM, 128 or 512 kB
memory backup NiCd accumulator 3,6 V, 60 mAh
printer electrothermal, CITIZEN MLT-288
customer and cashier display 2x segmented LCD
alphanumeric LCD 2x20 characters for cashier, segmented LCD for customer
keyboard 30 regular keys and 1 double key
1.2 System configuration
The Euro-500T Handy is designed as a portable electronic cash register. The main parameters of a portable cash register are: low
weight, small size and a guarantee of longevity without an external connection.
The E-500N 16-bit micro-controller with 11 I/O ports and 2 portable channels is the center of the cash register. The cash register
program is stored in the 256 kB EPROM. Depending on the program version in EPROM memory, the micro-controller works with
RAM memory with a capacity of either 128 or 512 kB.
System contains:
connecting circuits
micro-processing system
current time circuit
reset controller (reset control circuit)
circuit controlling power supply value
keyboard interface
display interface
printer interface
RS-232 serial interfaces for PC, scanner and electronic scales
interface for connecting external PC keyboard
circuits for power reduction
circuit for drawer opening
circuit for scanning paper ribbon end
back-light of cashier display (optional for segment cashier display)
back-light of customer display (optional)
fiscal memory with support circuits (optional)
external accumulator - battery box (optional)
1.3 Cash register block diagram
EPROM
256 kB
SRAM
128 (512) kB
8-bit data bus
19-bit address busA 0 - A 1 8
D 0 - D 7
Current
time circuit
RS 232
interface for PC
RS 232 inter-
face for scanner
and scales
External
PC keyboard
Power voltage
checking
Paper ribbon
present
checking
Display
Fiscal
memory
Printer
Keyboard
Control bleeding
current circuit
MICROCONTROLLER
E-500N